<template>
  <div class="bottom-menu">
    <CheckButton class="select-all" @checkBtnClick="checkBtnClick" v-model="isSelectAll"></CheckButton>
    <!-- <check-button :is-checked="isSelectAll" 
                   class="select-all">
                   @click.native="checkBtnClick">
    </check-button> -->
    <span>全选</span>
    <span class="total-price">合计: ¥{{totalPrice}}</span>
    <span class="buy-product" @click="calcClick">去计算({{$store.getters.cartCount}})</span>
  </div>
</template>

<script>
  import CheckButton from './CheckButton'

	export default {
		name: "BottomBar",
    components: {
		  CheckButton
    },
    computed: {
		  totalPrice() {
        const cartList = this.$store.getters.cartList;
        return cartList.filter(item => {
          return item.checked
        }).reduce((preValue, item) => {
          return preValue + item.count * item.newPrice
        }, 0).toFixed(2)
      },
      // checkLength(){
      //   return this.$store.getters.cartList.find(item=>item.checked).length
      //   // return this.cartList.filter(item => item.checked).length
      // },
      isSelectAll() {
        // return this.$store.getters.cartList.find(item => item.checked === false) === undefined;
        // if(this.$store.getters.cartList.length === 0) return false
        // 1.使用find函数
        // return !this.$store.getters.cartList.find(item => !item.checked)

        // 2.使用filter
        // return !(this.$store.getters.cartList.filter(item => !item.checked).length);
        // 这个性能不算特别好

        // 3.普通遍历
        // for(let item of this.$store.getters.cartList){
        //   if(!item.checked){
        //     return false
        //   }
        // }
        // return true

        return this.$store.getters.cartList.find(item => item.checked === false) === undefined;

      }
    },
    methods: {
      checkBtnClick() {
        // 1.判断是否有未选中的按钮
        let isSelectAll = this.$store.getters.cartList.find(item => !item.checked);

        // 2.有未选中的内容, 则全部选中
        if (isSelectAll) {
          this.$store.state.cartList.forEach(item => {
            item.checked = true;
          });
        } else {
          this.$store.state.cartList.forEach(item => {
            item.checked = false;
          });
        }
      },
      calcClick(){
        if(!this.isSelectAll){
          this.$toast.show('请选择需要购买的商品',2000)
        }
      }
    }
	}
</script>

<style scoped>
  .bottom-menu {
    width: 100%;
    height: 44px;
    background-color: #eee;
    position: fixed;
    bottom: 50px;
    left: 0;
    box-shadow: 0 -2px 3px rgba(0, 0, 0, .2);
    font-size: 14px;
    color: #888;
    line-height: 44px;
    padding-left: 35px;
    box-sizing: border-box;
  }

  .bottom-menu .select-all {
    position: absolute;
    line-height: 0;
    left: 12px;
    top: 13px;
  }

  .bottom-menu .total-price {
    margin-left: 15px;
    font-size: 16px;
    color: #666;
  }

  .bottom-menu .buy-product {
    background-color: orangered;
    color: #fff;
    width: 100px;
    height: 44px;
    text-align: center;
    line-height: 44px;
    float: right;
  }
</style>
